ok, I have an MSI K9N PLatinum SLI (VRM Chip has heatsink with Heatpipe from it) some reason not all the revisions of this board has one.

Anyway, when I first built this system. i never actually broke it in, 2 weeks into running i was having lockups (found the problem to be Everest Monitoring software), anyway, shortly after the CPU Died or the Mainboard, MSI Replaced both my mainboard and the CPU, the AMD AthlonX2 6000+.

as soon as I got it back and did more look, I noticed temps were out of control with the stock cooler (in a 65 Degree AC'd Room). failed OCCT/Prime95, or I'd have to stop the test before temps hit the red zone. Bought a Zalman 9700NT AMD Version to slap on it, problem solve.

I just re-installed all my mainboard/GPU drivers and untilities (nVidia and eVGA) because of a ransomware incident (Windows Police), infected alot of system32/dll files and the dlls in the cache, so AVG Put those in the vault.

anyway, re-inflated the DLLs from the XP CD then re-ran SP3 install.

Re-installed the Mobo (Actually i think i updated them, lol, been a while), removed AMDs Dual Core Optimizer Service since Sp3 has one. and updated the CPU driver while I was at it, Updated to the latest eVGA drivers as well.

So I started running the NVidia Systems Monitor.

And Noticed that My MCP TEMP is IDLING at 64/65 Degree's Celcius. ok, thats not good, I havent been able to get a under load reading, but I dont think it would be too good.

other temps are fine, ie. its 80 degrees in my apt. right now:
CPU Cores 1 and 2: 38/40
GPU Core : 59
HDD 1, 2, and 3: 40/39/40

Im running some background programs that are using memory and 20% of core 2, but thats it.

so why is the MCP Temp so high?

Maybe your northbridge chip's TIM has dried out and turned to plaster. Or completely evaporated away. Or was never applied in the first place. The only way you would know is to look.

Turn the a/c down!

Lol @ Kryptonite. Refresh my AMD knowledge: MCP = Southbridge? I'm assuming you got some sort of active cooling on that (an itsy bitsy fan maybe)

You might consider popping off the fan, re-applying some thermal compound and putting on a fan with some heatpipes, like this one. http://www.newegg.com/Product/Product.aspx?Item=N82E16835116018. This should be alot better than anything they would include on the board.